US3733199A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Photographic composition of sodium and potassium ions for treating direct positive emulsions
Assignee: Eastman Kodak Co
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Filing: 1971-06-14
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Granted: 1973-05-15
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Expires: 1991-06-14
Abstract
Abstract A DIFFUSION TRANSFER PROCESS COMPRISES DEVELOPING AN EXPOSED DIRECT POSITIVE EMULSION IN THE PRESENCE OF A SILVER HALIDE SOLVENT, A SILVER HALIDE DEVELOPING AGENT, A DEVELOPMENT RESTRAINER SUCH AS BENZOTRIAZOLE AND SODIUM AND POTASSIUM AS IONS OR IN COMBINED FORM E.G. AS COMPOUNDS, INCLUDING COMPLEXES. THE SODIUM AND POTASSIUM ARE PRESENT IN A CONCENTRATION OF ABOUT 8 TO ABOUT 27 MOLE PERCENT POTASSIUM AND ABOUT 92 TO ABOUT 73 MOLE PERCENT SODIUM, BASED ON THE TOTAL MOLES OF SODIUM AND POTASSIUM OF ABOUT 5 TO A ABOUT 30%, BY WEIGHT, DRY BASIS OF TOTAL DEVELOPING COMPOSITION.
Inventors
- 👤 P Crough
- 👤 H Snyder
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 08:56
CPC Classifications
G; G03; G03C; G03C8/00; G03C8/02; G03C8/04; G03C8/06
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-05-14 | 1976-11-13 | 1977-05-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-05-14 | 1980-11-13 | 1981-05-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-05-14 | 1984-11-13 | 1985-05-15 | $7700.00 | Window Closed / Lapsed |